1. Field of the Invention
The present invention relates to a noise suppression member. More specifically, the invention relates to a multipart structure suitable for placement about the coils of a spring to suppress noise occurring during usage thereof.
2. Background of the Invention
Springs are used for a variety of applications, such as motor vehicle suspension systems. When used in vehicle suspension system a coil spring is placed between a control arm of a vehicle, upon which a wheel is mounted, and a portion of the vehicle frame. During vehicle operation, if the spring is deflected a sufficient distance contact between individual coils of the spring occurs and creates a noise which is best described as a squeak or clatter. The noise, while not affecting the performance of the vehicle, is irritating to the vehicle owner and may result in increased consumer complaints and warranty costs.
In an attempt to eliminate spring noise, an extruded tubular sheath having a longitudinal slit in a side thereof was placed over the spring coils to provide a cushion between the coils. While producing some success in noise reduction during spring operation, it proved difficult to keep the extruded tubular sheath on the spring because placing a generally straight and elongated tubular sheath over generally circular spring coils causes the inner portion of the tubular sheath to be placed in compression while the outer portion is placed in tension thereby creating wrinkles and a gap or opening in the tubular sheath adjacent the slit.
Additionally, spring dynamics during operation of the vehicle, i.e. elongation and compression of the spring, caused the tubular sheath to work its way free of the spring. As the spring moves from a fully compressed position to a fully elongated position the overall diameter of the spring changes, it is this change in diameter coupled with the preloading of the tubular sheath which causes the tubular sheath to work its way off of the spring.
Accordingly, it is an object of the present invention to provide a noise suppression device that can be disposed about the coils of a spring to reduce unwanted spring noise.
Another object of the invention is to provide a noise suppression device which can be disposed about and remain on the spring which will last and be functional as long as the life of the vehicle.
Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the pending claims taken in conjunction with the accompanying drawings.